本文關(guān)鍵詞： 泡沫法 團(tuán)聚劑 細(xì)微顆粒物 團(tuán)聚機理 數(shù)值模擬　出處：《青島大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：泡沫法團(tuán)聚細(xì)微顆粒物屬于化學(xué)方法團(tuán)聚細(xì)微顆粒物的一種,主要是利用各種化學(xué)試劑通過化學(xué)反應(yīng)或化學(xué)鍵作用促使細(xì)顆粒凝聚變?yōu)榇箢w粒團(tuán)。泡沫法不同于霧化液滴法,主要是通過霧化噴嘴使得添加發(fā)泡劑與穩(wěn)泡劑的團(tuán)聚液,霧化成大量氣泡和液滴,形成的泡沫增大了團(tuán)聚液與含塵氣流接觸的比表面積。隨著粉塵細(xì)微顆粒物不斷碰撞氣泡并粘附在氣泡表面,導(dǎo)致氣泡破碎,進(jìn)而團(tuán)聚細(xì)微顆粒物。首先進(jìn)行粘附細(xì)微顆粒物所需氣泡條件的研究,對氣泡直徑與團(tuán)聚顆粒物的能力進(jìn)行估算。通過CCD拍攝精細(xì)霧化噴嘴噴出的團(tuán)聚液泡沫流動過程,利用MATLAB處理圖片,得出霧化氣泡直徑和密度(截面上數(shù)量)大小。結(jié)果表明,采用同一噴嘴,發(fā)泡劑(十二烷基苯磺酸鈉)和穩(wěn)泡劑(椰油酸二乙醇酰胺)的添加增強了團(tuán)聚液霧化液滴形成氣泡,增加了霧化泡沫的數(shù)量;以PAM(非離子型聚丙烯酰胺)為團(tuán)聚劑的溶液形成的氣泡直徑偏小,且霧化后液滴和氣泡的數(shù)量密度大,粒徑主要分布在小于200μm范圍;XTG(黃原膠)團(tuán)聚液氣泡直徑偏大,CMC(羧甲基纖維素鈉)團(tuán)聚液氣泡直徑介于兩者之間。0.2%CMC團(tuán)聚液氣泡直徑均勻,氣泡和液滴數(shù)量多;在軸向距噴嘴25cm處,氣泡破碎和聚合趨于穩(wěn)定;噴嘴直徑0.5mm時,氣泡直徑大多分布在100~300μm粒徑范圍,符合理論計算的團(tuán)聚PM2.5的氣泡條件;隨著溶液溫度的升高,直徑在0~300μm內(nèi)的氣泡顆粒數(shù)量明顯增大。其次,通過自行設(shè)計建立的實驗系統(tǒng)進(jìn)行實驗研究,分析泡沫團(tuán)聚劑種類、濃度、溫度,噴淋層數(shù)及除霧器層數(shù)等因素對細(xì)微顆粒物脫除效率的影響。實驗發(fā)現(xiàn)泡沫團(tuán)聚劑能有效的將煙氣中細(xì)微顆粒物粘附團(tuán)聚形成顆粒團(tuán)。在PAM、CMC和XTG三種團(tuán)聚劑中,XTG的團(tuán)聚作用最為明顯;經(jīng)0.1%XTG團(tuán)聚液噴淋團(tuán)聚后的排氣中經(jīng)孔板除霧器顆粒物濃度降低為10.6 mg/m3;XTG團(tuán)聚液在80℃下,對細(xì)微顆粒物團(tuán)聚后脫除效率最高,排煙顆粒物濃度為9.4 mg/m3;增加噴淋層數(shù)可以有效的減少團(tuán)聚除霧后尾氣中顆粒物濃度;增加孔板除霧器數(shù)量對團(tuán)聚效果影響不大。最后,結(jié)合實驗中的進(jìn)出口參數(shù),利用Fluent軟件中的PBM模型進(jìn)行數(shù)值模擬研究。僅對噴淋段與順流段進(jìn)行模擬。參照實驗結(jié)果來調(diào)整模型及其參數(shù),獲得符合實驗工況的流動模擬,從而分析得到泡沫法團(tuán)聚細(xì)微顆粒物的機理;隨泡液比的增加,顆粒物團(tuán)聚作用更為明顯,氣泡對團(tuán)聚起主要的作用;團(tuán)聚液粘度增大對顆粒物團(tuán)聚起促進(jìn)作用,但過大會影響霧化從而影響團(tuán)聚。本研究的泡沫團(tuán)聚細(xì)微顆粒物的機理是滿足所需氣泡條件下,細(xì)微顆粒物不斷粘附浸沒在氣泡表面,當(dāng)團(tuán)聚了顆粒物的氣泡上重力與表面張力間平衡破壞后,氣泡破碎,細(xì)微顆粒物聚合為大顆粒團(tuán),固相粒徑增大,利于后部的除霧器或除塵器脫除顆粒物。
[Abstract]:Foam agglomeration of fine particles belongs to one of the chemical methods of agglomeration of fine particles. It mainly uses a variety of chemical reagents to make fine particles agglomerate into large particles by chemical reaction or chemical bond action. Foam method is different from atomization liquid drop method. Mainly through atomizing nozzles, the agglomerates with foaming agent and foam stabilizer are added to atomize a large number of bubbles and droplets. The resulting foam increases the specific surface area of the agglomerate in contact with the dust-containing airflow. As fine particles of dust continuously collide with the bubble and adhere to the surface of the bubble, the bubble breaks up. Then the fine particles were agglomerated. Firstly, the bubble conditions needed to adhere to the fine particles were studied, and the bubble diameter and the ability of agglomeration particles were estimated. The foam flow process of the agglomerates ejected from fine atomization nozzles was photographed by CCD. The diameter and density of atomized bubbles (number of sections) are obtained by MATLAB. The results show that the same nozzle is used. The addition of foaming agent (sodium 12 alkylbenzenesulfonate) and foaming stabilizer (coconut oil diethanolamide) enhanced the atomizing liquid droplets of agglomerates to form bubbles and increased the number of atomized foam. The bubble diameter formed by the solution of PAM (non-ionic polyacrylamide) as agglomeration agent is small, and the number density of droplets and bubbles after atomization is large. The diameter of the bubble in XTG agglomeration is larger than 200 渭 m. The diameter of CMC (sodium carboxymethyl cellulose) agglomeration is between the two. The diameter of the bubble is uniform, the number of bubbles and droplets is large, and the diameter of bubbles and droplets is more than 25cm from the nozzle, and the diameter of the bubble is larger than 200 渭 m, and the diameter of CMC (sodium carboxymethyl cellulose) agglomeration is between the two. When the diameter of the nozzle is 0.5 mm, the bubble diameter is mostly distributed in the diameter range of 100 渭 m to 300 渭 m, which accords with the theoretical calculation of the bubble condition of agglomeration PM2.5, and increases with the increase of solution temperature. The number of bubble particles in the diameter of 0 ~ 300 渭 m is obviously increased. Secondly, through the experimental system designed by ourselves, the types, concentration and temperature of foam agglomerators are analyzed. The effect of spray layer number and mist layer number on the removal efficiency of fine particles was studied. It was found that foam agglomeration agent could effectively agglomerate fine particles in flue gas to form particles. The agglomeration effect was the most obvious. After spray agglomeration with 0.1% XTG agglomeration solution, the concentration of particulate matter decreased to 10.6 mg / m ~ (3) XTG agglomerate in the exhaust gas from the porous plate precipitator. At 80 鈩，

本文編號：1555289